POS0026 THE INDEPENDENT INFLUENCE OF SEX ON THE DISEASE IMPACT DOMAINS IN PSORIATIC ARTHRITIS IS MODEST, ONCE CONFOUNDERS ARE TAKEN INTO ACCOUNT
Authors: A. Ortolan, A. Capacci, A. Zoli, S. DI Murro, F. Cristiano, P. Cerasuolo, R. La Ferrara, L. Lanzo, C. Tur, P. Rubortone, L. Verardi, G. Calabrese, P. Aquilino, G. Peluso, M. A. D’agostino
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Female sex has been associated to higher disease impact in psoriatic arthritis (PsA), as measured by the PsA Impact of Disease (PSAID) questionnaire. However, it is unclear whether sex can influence all different PSAID domains (physical and psychological), or some of them, and whether confounders might be responsible for this association. <h3>Objectives</h3> 1) to assess the impact of sex on each of the 12 PSAID domains, and 2) to correct this association for known confounders, including fibromyalgia, to evaluate the independent effect of sex on each of them. <h3>Methods</h3> Consecutive PsA patients, classified according to CASPAR criteria, attending our tertiary center between January and December 2022 were included. Demographic data, patient history, disease activity indices [Visual Analogue Scale (VAS) of pain and disease activity, Disease Activity in PsA (DAPSA) score) and functional indices (Health Assessment Questionnaire, HAQ) were collected. Impact of the disease was assessed by PSAID 12. Patients' characteristics were compared between men and women with descriptive statistics. Multiple linear regression models were built, having the 12 PSAID domains and total PSAID as outcomes (=13 outcomes), and sex as main independent variable. The crude and adjusted association between sex and each of the outcomes were studied. Namely, models were adjusted for: 1) age and DAPSA; 2) age, DAPSA and fibromyalgia. R<sup>[2]</sup> was used to measure the proportion of PSAID variance explained by sex. F-change test was used to evaluate if the addition of fibromyalgia as a confounder significantly contributed to improve the model fit. <h3>Results</h3> A total of 190 PsA patients were enrolled, 42% males, disease duration was 7.5±7.6 years. VAS pain, VAS disease activity, HAQ, all the 12 PSAID domains, and DAPSA were significantly higher in females (p&lt;0.05). The univariate models having the PSAID domains as outcomes, and sex as independent variable, showed significant negative associations between the two (<b>Table 1</b>). R<sup>2</sup> values highlighted that a small proportion of the PSAID variance was explained by sex only (R<sup>2</sup>0.04-0.15). In the models corrected for age and DAPSA (model group 1, <b>Table 1</b>), male sex was a negative independent predictor of some of the PSAID domains (fatigue, work and leisure, functional capacity, discomfort, sleep disturbance, coping and depression). The addition of fibromyalgia as a confounder (model group 2, <b>Table 1</b>) significantly improved the model fit for many of the PSAID outcomes, and male sex remained independently associated only to functional capacity and coping. <h3>Conclusion</h3> Sex alone is not able to explain PSAID variability, although it could have a higher impact on functional capacity and coping. More research is needed in order to understand the contextual factors that could explain the differences in PsA impact between men and women. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.